This invention relates to an electronic image transfer device which stores image signals formed by an image sensor and prints on a medium an image represented by the stored signals and a thermal transfer donor film used therein. More particularly, an electronic image transfer device of the present invention is of a compact, portable type, having an image sensor and an image printer which are designed to scan within a single plane such that the image detected on an original by the image sensor and stored as image signals is printed by the printer on any medium, thereby obviating the need to store specially processed copy paper in its interior. The thermal transfer donor film of the present invention for use in such an electronic image transfer device has transparent and donor areas alternately such that the image sensor and the printer can be operated to scan within a single plane.
Since copiers and transfer devices are used nowadays for different purposes and under varied conditions, it is desired to provide compact, hand-held models of these devices. Conventionally, however, such devices make use of a heat-sensitive method and a image cannot be printed unless use is made of specially processed heat-sensitive recording paper. For this reason, a roll of such processed paper is usually contained inside the device and this has the disadvantage of complicating the maintenance operation. Moreover, printed paper is discharged continuously from such a device and the work of cutting it into desired sizes or combining them together can be extremely troublesome.
With the so-called plane paper copiers (PPC), specially treated paper is not required and the basic process is not different from the conventional method. In other words, a latent image of an original document is formed on a photosensitive body and after a toner image is electrostatically formed, it is transferred to a copying medium such as paper. In order to carry out this series of processes, however, the device must include a document table which serves as input surface, a photosensitive body on which an image is formed electrostatically, and a transfer device for transferring a toner image onto the copying medium. These requirements make it extremely difficult to design a compact device. Although attempts have been made to develop a device comprising an image sensor for detecting an image on an original document and a printer for printing the image detected by the image sensor, thereby obviating the need for a photosensitive body, the image sensor and the printer have usually been disposed one-dimensionally in order to reduce cost. As a result, a plurality of driving means are required to operate these components and this again prevents reduction of the overall size of the device.